The referenced patents and literature describe various types of microprocessor controlled systems to monitor and furnish control signals for operating events in internal combustion engines, and particularly in internal combustion engines coupled to or forming part of a power train of a vehicle. Fixed wired computers to control operating events in an automotive vehicle, or in the internal combustion (IC) engine therefor, is described in the reference U.S. Pat. No. 4,063,539; fixed wired computers or signal processors have a disadvantage with respect to microprocessor control signals in that the computer is poorly adaptable to universal use since the system is designed for a particular engine and vehicle combination, and thus cannot be individually changed to fit various types of engines or models of vehicles with which the engine is to be used, and which all introduce different parameters which vary the respective outputs from the computer, although the basic computational methods may all be the same. Microprocessor systems have the advantage of being readily adaptable to different types of engines and power train systems. They are subject to improvement, however, since they are coupled to a multiplicity of input units and also output units, and thus must retain a substantial data base and hence memory locations, which are retained in fixed memories, for example read-only memories (ROMs). Comparatively complex programs are necessary to process externally applied signals by carrying out extensive, and hence slow computational steps. If the engine operates at high speed, the accuracy of signal processing by mathematical calculations suffers, unless the number of bits is increased and the cycling or clock time is made correspondingly high. To control, for example, a fuel injection system, more than eight bits are required for accurate computation although, usually, the microprocessors which are readily adaptable for automotive use operate with eight-bit words.
The referenced U.S. Pat. Nos. 4,204,256 and 4,250,858, as well as the German Disclosure Document DE-OS No. 29 00 111, describe microprocessor-input/output combinations in which, to relieve the microprocessor of calculation tasks, the input/output units are so arranged that they themselves can carry out computational operations and counting. In such input/output units, a problem similar to that of a wired program arises in that, for different types of IC engines, different parameters must be sensed; the type and number of parameters may depend on the engines and on the desires or design requirements of the engine manufacturer, and thus may require processing of different signals related to different engine parameters. Yet, to permit mass production of input/output units suitable for a number of different engines and, also, to permit interchangeability, it is desirable to provide input/output units which are applicable for various types of apparatus and engines, or engine-vehicle combinations, which, looked at from point of view of signal processing, means various types of power train systems.